1. Field of the Invention
The invention relates to a method and an apparatus for operating a printer. Printers are used for a wide variety of purposes, particularly including as a documentation unit for a tachograph, specifically a digital tachograph, in particular. A digital tachograph stores all the relevant records in a black box for a prescribed period, specifically one year, and on a personal driver's card, which is in the form of a chip card, for 28 days. Thus, driving times, working hours, standby times and rest times, and also interruptions thereto and distances covered, are stored. In addition, maximum speeds within the last 24 hours are recorded. All of the data can be read digitally by control authorities or the owner of the vehicle in line with prescribed legal regulations. In addition, the vehicle driver can print a paper record if required. For this purpose, the printer is provided.
2. Description of the Prior Art
The printing medium is usually paper and is usually stored in the form of a printing medium unit in the form of a roll in a receptacle in the printer. To date, the imminent depletion of the printing medium has been indicated to the user by an edge stripe identified by an appropriate color at the end of the printing medium.
EP 1 323 654 A1 discloses a system for detecting a low paper condition for a printer paper supply, which comprises a signal emitter for emitting a signal into a paper supply and a variably activated receiver for generating a paper supply signal, the variably activated receiver being arranged at a location for selectively receiving the signal emitted by the signal emitter in relation to the level of the paper in the supply, wherein the signal emitter is an infrared source.